The BERING Slim Solar collection ticks to the rhythm of nature, using light as its infinite, environmentally-friendly energy source. The solar cell under the watch face converts light of any kind into electrical energy and stores it in a rechargeable secondary battery. No battery charge is required. The watch has a power reserve so that, once fully charged, it runs for 6-12 months, even if stored in complete darkness during this time. Scratch resistant sapphire crystal, brushed stainless steel and the finest straps in mesh or calfskin, create a product that not only feels good, it looks good too.